In the clinical practice survey of the first phase of the program, the GH cut off level after a OGTT to discard acromegaly in patients with elevated or equivocal serum IGFI levels at diagnosis was set ≤ 0.4 μg/L by 53% of the surveyed endocrinologists and < 1 μg/L by 37% of them, depending mainly on the sensitivity of the assay. The gene discussed is IGF1; the disease is acromegaly.